School health records of 332 children through the eighth grade were examined in a retrospective c... more School health records of 332 children through the eighth grade were examined in a retrospective comparative analysis of physical health status and school achievement of children from Head Start and Free School Lunch Programs. The objective was to determine if nutrition early in the lives of children as a part of a comprehensive health and education program such as Head Start produces greater or different benefits for disadvantaged children than nutrition intervention later through free lunches when the child enters school. Cross-sectional longitudinal, and case-study approaches were used in the analysis. A group of no-food-program disadvantaged children and a group of advantaged children served as comparisons. Results showed that advantaged children performed better on all parameters of school achievement and health status compared with the disadvantaged children, regardless of the form of intervention. Measures of school achievement of Head Start and Free Lunch children did not differ from those of the disadvantaged comparison group, but there were significant differences in measures of health status between the disadvantaged groups. Fewer boys from Project Head Start fell below the 25th percentile for height compared with boys in the Free Lunch Program. Head Start children also scored higher in physical fitness and had fewer reported absences from school due to illness.
Rats reduce their food intake after ingestion of a small amount of an amino acid imbalanced (AA-I... more Rats reduce their food intake after ingestion of a small amount of an amino acid imbalanced (AA-IMB) diet that induces a pronounced amino acid deficiency. Two hours after ingesting a threonine-IMB diet, just when food intake is depressed significantly, the concentration of threonine is decreased in some but not all brain areas. Neural recognition of this decrease in the limiting amino acid is thought to be the first step in the anorectic responses to AA-IMB diets. To identify the regions of the brain that may be activated upon recognition of an AA-IMB diet, we examined the temporal-spatial distribution of Fos immunoreactive neurons at intervals after introduction of either threonine-IMB or control diets. We found that Fos immunoreactivity in the anterior piriform cortex and immediately surrounding areas, along with the infralimbic cortex, was increased selectively early (by 2 h) after introduction of the AA-IMB diet, and remained elevated through 3 h. The anterior piriform cortex is believed to function in neural recognition of amino acid deficiency. Fos immunoreactivity in the AA-IMB group increased over the control diet groups somewhat later in the dorsomedial nucleus of the hypothalamus. We hypothesize that these areas in the rostral forebrain may serve as neural relays in the early phases of the anorectic responses that occur upon recognition of amino acid deficiency.
We compared the vitamin B-6 status of 12-wk-old rats (n = 12) fed excess (1400 mg/kg diet) or the... more We compared the vitamin B-6 status of 12-wk-old rats (n = 12) fed excess (1400 mg/kg diet) or the recommended level (7 mg/kg diet, control) of pyridoxine (PN) hydrochloride to test if excess vitamin B-6 would cause tissue depletion of pyridoxal phosphate (PLP), the active coenzyme form of vitamin B-6. Plasma PLP, tryptophan-load test results, food intake, and tissue and body weights were not different at wk 6. Red blood cell endogenous alanine aminotransferase activity and PLP concentration were elevated (P less than 0.01) in rats fed 1400 mg PN.HCl/kg diet. In contrast, PLP concentration in muscle was significantly lower (P = 0.01) in rats fed excess vitamin B-6 (9.7 +/- 0.8 nmol/g, mean +/- SEM) than in controls (14.9 +/- 1.4). PLP concentration in other tissues, including plasma, was not affected. In rats fed excess vitamin B-6, pyridoxal was increased in all tissues examined (P less than 0.05), and total vitamin B-6 was increased in plasma, red blood cells and kidneys (P less than 0.05). Total glycogen phosphorylase (a + b) activity in the gastrocnemius was not affected, but phosphorylase a activity was increased in rats fed excess vitamin B-6 (P = 0.025). Concentrations of dopamine and metabolites in the caudate nucleus of the basal ganglia were not affected. A transient, but significant, elevation in acoustic startle response, a central nervous system reflex, was observed in rats fed excess vitamin B-6. The depletion in muscle PLP could not hae been predicted by either plasma or red blood cell PLP concentration, although the latter did reflect vitamin B-6 intake.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino acid-imbalanced (IMB) diets induce an acute amino acid deficiency and hypophagic responses ... more Amino acid-imbalanced (IMB) diets induce an acute amino acid deficiency and hypophagic responses in most animals. The neural circuits underlying these responses are unknown. To ascertain potential neural circuits involved in the recognition of IMB, we measured the concentrations of norepinephrine, dopamine, serotonin, their metabolites and 20 amino acids in 14 rat brain areas in three studies. Rats were prefed a basal diet with L-amino acids as the protein source for at least 1 wk. For the experiments, either threonine or isoleucine IMB diet was offered for 2.5 or 3.5 h. Brains were taken before (using a mildly IMB diet) or after (using moderately or severely IMB diet) food intake was significantly (P < 0.05) depressed. Brain areas were dissected and analyzed for monoamines, metabolites and amino acids. Only in the anterior piriform cortex (APC), a brain area that may contain the amino acid chemosensor, was the limiting amino acid lower in IMB groups than in controls across all of the experiments. Before the onset of the anorectic response to the IMB diets, monoaminergic activity was affected in areas that have recognized monosynaptic connections with the APC. We propose a circuit for the neural responses in the initial recognition of acute amino acid deprivation that begins with activation of the APC and includes areas in the hindbrain and hypothalamus. After a significant hypophagic response, serotonergic indicators were altered in areas of the taste pathway and the limbic system. These results suggest that different circuits mediate the initial recognition and secondary conditioned responses to IMB diets.
Conditioned taste aversion presumably plays a role in the anorectic responses to amino acid-imbal... more Conditioned taste aversion presumably plays a role in the anorectic responses to amino acid-imbalanced diets that induce acute amino acid deficiency. The serotonin3 (5-HT3) receptor antagonists, tropisetron (Trop), MDL-72222 (MDL), and ondansetron, increase intake of imbalanced amino acid diets. Therefore, we tested whether 5-HT3 receptor antagonists would block an aversion to powdered saccharin after it was included in an amino acid-imbalanced diet. Rats were given an intraperitoneal injection of Trop, MDL, or vehicle (Veh), just before introducing one of four diets: imbalanced amino acid diet +/- saccharin (Imb or ImbSac) or a balanced (corrected) diet +/- saccharin (Cor or CorSac). Subsequent aversion to saccharin was shown in preference tests using Cor and CorSac. Saccharin preference was significantly decreased (8.3% on test day 1) in the Veh/ImbSac group, but the Trop/ImbSac group's saccharin preference (57.8%) was similar to controls (49.6-70.3%); MDL also blocked the aversion to saccharin after ImbSac. This confirms previous reports of conditioned taste aversions with amino acid limitation and suggests a role for the 5-HT3 receptor in the development of these aversions.
Indispensable amino acids are neither synthesized nor stored in animals and are rapidly depleted ... more Indispensable amino acids are neither synthesized nor stored in animals and are rapidly depleted when not provided by the diet. To maintain homeostasis, organisms must sense deficiency of an indispensable amino acid and implement a repletion strategy. In rats and birds, the anterior piriform cortex houses the detector, but its mechanism has evaded description for >50 years. Recently, rapid detection of amino acid depletion was shown behaviorally when naïve animals, pre-fed a low nitrogen diet, terminated their first deficient meal within 20 min. The general amino acid control system of yeast, which is activated by amino acid deprivation via deacylated tRNA, was found to be active in rodent brain, showing conservation of amino acid sensory mechanisms across eukaryotic species.
We compared the vitamin B-6 status of 12-wk-old rats (n = 12) fed excess (1400 mg/kg diet) or the... more We compared the vitamin B-6 status of 12-wk-old rats (n = 12) fed excess (1400 mg/kg diet) or the recommended level (7 mg/kg diet, control) of pyridoxine (PN) hydrochloride to test if excess vitamin B-6 would cause tissue depletion of pyridoxal phosphate (PLP), the active coenzyme form of vitamin B-6. Plasma PLP, tryptophan-load test results, food intake, and tissue and body weights were not different at wk 6. Red blood cell endogenous alanine aminotransferase activity and PLP concentration were elevated (P less than 0.01) in rats fed 1400 mg PN.HCl/kg diet. In contrast, PLP concentration in muscle was significantly lower (P = 0.01) in rats fed excess vitamin B-6 (9.7 +/- 0.8 nmol/g, mean +/- SEM) than in controls (14.9 +/- 1.4). PLP concentration in other tissues, including plasma, was not affected. In rats fed excess vitamin B-6, pyridoxal was increased in all tissues examined (P less than 0.05), and total vitamin B-6 was increased in plasma, red blood cells and kidneys (P less th...
Transition from a normal- (NP) to a high-protein (HP) diet induces a rapid depression in food int... more Transition from a normal- (NP) to a high-protein (HP) diet induces a rapid depression in food intake and a progressive but incomplete return to the initial intake during the succeeding days. The aim of this study was to determine which CNS regions are involved in the HP diet-induced satiety in rats. Brains were collected from 3 groups of adult rats after habituation to an NP diet (21 d), during the transition phase to a HP diet (2 d), or after habituation to the HP diet (21 d). Fos expression was measured in several brain areas that are involved in the control of food intake (solitary tract nucleus, anterior piriform cortex, lateral hypothalamus, arcuate nucleus, posterior para ventricular nucleus, medio ventral hypothalamus, dorso medial hypothalamus, amygdala, and accumbens nucleus). Changes occurred in the majority of these regions during the transition period from the NP diet to the HP diet. After habituation to the HP diet, significant changes in Fos expression were restricted ...
Rats can adjust their nutrient intake in response to nutritional deficiency. This phenomenon has ... more Rats can adjust their nutrient intake in response to nutritional deficiency. This phenomenon has been described extensively for sodium deficiency, whereas other nutrient deficiencies have not been explored thoroughly. Essential amino acid (EAA) deficiency represents a relevant model to describe adaptive changes in behavior resulting from deficiency. The purpose of these experiments was to examine more closely the behavioral responses that occur as a result of lysine (LYS) and threonine (THR) deficiency. Licking to LYS, THR, glycine and distilled water during 10-s trials was measured in control (CON) and EAA-deficient rats. Licking tests were conducted both before and after 23-h intake tests. Although EAA-deficient rats did not show increased licking to the deficient EAA in any of the brief-access tests, in all cases, they did initiate significantly more overall trials than did CON. The EAA-deficient rats also had elevated intake of the deficient EAA in long-duration tests. These fin...
The present study investigated the relationship between endogenous CCK and serotonin (5-HT) in fa... more The present study investigated the relationship between endogenous CCK and serotonin (5-HT) in fat-induced satiety. Male Wistar rats with duodenal cannulas were adapted to eating 6 h/day along with receiving an infusion of saline or one of two isocaloric solutions (10 ml, 1 kcal/ml, 0.45 ml/min) varying in fat and carbohydrate content (20 or 80% energy from fat). Rats were infused 10 min after food presentation. The satiation/satiety response was determined from measures of meal size (MS), intermeal interval (IMI), and total food intake (TFI). Infusion with either fat solution reduced MS compared with saline; however, the 80% fat infusate reduced TFI and lengthened the IMI compared with saline and the 20% fat infusate. CCK and 5-HT involvement in fat-induced satiety was investigated by preceding the 80% fat infusate with CCK and/or 5-HT3 receptor antagonists Devazepide (Dev) and Tropisetron (Trop). A CCK releaser, trypsin inhibitor (TI), was added to the 20% fat infusate to enhance ...
School health records of 332 children through the eighth grade were examined in a retrospective c... more School health records of 332 children through the eighth grade were examined in a retrospective comparative analysis of physical health status and school achievement of children from Head Start and Free School Lunch Programs. The objective was to determine if nutrition early in the lives of children as a part of a comprehensive health and education program such as Head Start produces greater or different benefits for disadvantaged children than nutrition intervention later through free lunches when the child enters school. Cross-sectional longitudinal, and case-study approaches were used in the analysis. A group of no-food-program disadvantaged children and a group of advantaged children served as comparisons. Results showed that advantaged children performed better on all parameters of school achievement and health status compared with the disadvantaged children, regardless of the form of intervention. Measures of school achievement of Head Start and Free Lunch children did not differ from those of the disadvantaged comparison group, but there were significant differences in measures of health status between the disadvantaged groups. Fewer boys from Project Head Start fell below the 25th percentile for height compared with boys in the Free Lunch Program. Head Start children also scored higher in physical fitness and had fewer reported absences from school due to illness.
Rats reduce their food intake after ingestion of a small amount of an amino acid imbalanced (AA-I... more Rats reduce their food intake after ingestion of a small amount of an amino acid imbalanced (AA-IMB) diet that induces a pronounced amino acid deficiency. Two hours after ingesting a threonine-IMB diet, just when food intake is depressed significantly, the concentration of threonine is decreased in some but not all brain areas. Neural recognition of this decrease in the limiting amino acid is thought to be the first step in the anorectic responses to AA-IMB diets. To identify the regions of the brain that may be activated upon recognition of an AA-IMB diet, we examined the temporal-spatial distribution of Fos immunoreactive neurons at intervals after introduction of either threonine-IMB or control diets. We found that Fos immunoreactivity in the anterior piriform cortex and immediately surrounding areas, along with the infralimbic cortex, was increased selectively early (by 2 h) after introduction of the AA-IMB diet, and remained elevated through 3 h. The anterior piriform cortex is believed to function in neural recognition of amino acid deficiency. Fos immunoreactivity in the AA-IMB group increased over the control diet groups somewhat later in the dorsomedial nucleus of the hypothalamus. We hypothesize that these areas in the rostral forebrain may serve as neural relays in the early phases of the anorectic responses that occur upon recognition of amino acid deficiency.
We compared the vitamin B-6 status of 12-wk-old rats (n = 12) fed excess (1400 mg/kg diet) or the... more We compared the vitamin B-6 status of 12-wk-old rats (n = 12) fed excess (1400 mg/kg diet) or the recommended level (7 mg/kg diet, control) of pyridoxine (PN) hydrochloride to test if excess vitamin B-6 would cause tissue depletion of pyridoxal phosphate (PLP), the active coenzyme form of vitamin B-6. Plasma PLP, tryptophan-load test results, food intake, and tissue and body weights were not different at wk 6. Red blood cell endogenous alanine aminotransferase activity and PLP concentration were elevated (P less than 0.01) in rats fed 1400 mg PN.HCl/kg diet. In contrast, PLP concentration in muscle was significantly lower (P = 0.01) in rats fed excess vitamin B-6 (9.7 +/- 0.8 nmol/g, mean +/- SEM) than in controls (14.9 +/- 1.4). PLP concentration in other tissues, including plasma, was not affected. In rats fed excess vitamin B-6, pyridoxal was increased in all tissues examined (P less than 0.05), and total vitamin B-6 was increased in plasma, red blood cells and kidneys (P less than 0.05). Total glycogen phosphorylase (a + b) activity in the gastrocnemius was not affected, but phosphorylase a activity was increased in rats fed excess vitamin B-6 (P = 0.025). Concentrations of dopamine and metabolites in the caudate nucleus of the basal ganglia were not affected. A transient, but significant, elevation in acoustic startle response, a central nervous system reflex, was observed in rats fed excess vitamin B-6. The depletion in muscle PLP could not hae been predicted by either plasma or red blood cell PLP concentration, although the latter did reflect vitamin B-6 intake.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino acid-imbalanced (IMB) diets induce an acute amino acid deficiency and hypophagic responses ... more Amino acid-imbalanced (IMB) diets induce an acute amino acid deficiency and hypophagic responses in most animals. The neural circuits underlying these responses are unknown. To ascertain potential neural circuits involved in the recognition of IMB, we measured the concentrations of norepinephrine, dopamine, serotonin, their metabolites and 20 amino acids in 14 rat brain areas in three studies. Rats were prefed a basal diet with L-amino acids as the protein source for at least 1 wk. For the experiments, either threonine or isoleucine IMB diet was offered for 2.5 or 3.5 h. Brains were taken before (using a mildly IMB diet) or after (using moderately or severely IMB diet) food intake was significantly (P < 0.05) depressed. Brain areas were dissected and analyzed for monoamines, metabolites and amino acids. Only in the anterior piriform cortex (APC), a brain area that may contain the amino acid chemosensor, was the limiting amino acid lower in IMB groups than in controls across all of the experiments. Before the onset of the anorectic response to the IMB diets, monoaminergic activity was affected in areas that have recognized monosynaptic connections with the APC. We propose a circuit for the neural responses in the initial recognition of acute amino acid deprivation that begins with activation of the APC and includes areas in the hindbrain and hypothalamus. After a significant hypophagic response, serotonergic indicators were altered in areas of the taste pathway and the limbic system. These results suggest that different circuits mediate the initial recognition and secondary conditioned responses to IMB diets.
Conditioned taste aversion presumably plays a role in the anorectic responses to amino acid-imbal... more Conditioned taste aversion presumably plays a role in the anorectic responses to amino acid-imbalanced diets that induce acute amino acid deficiency. The serotonin3 (5-HT3) receptor antagonists, tropisetron (Trop), MDL-72222 (MDL), and ondansetron, increase intake of imbalanced amino acid diets. Therefore, we tested whether 5-HT3 receptor antagonists would block an aversion to powdered saccharin after it was included in an amino acid-imbalanced diet. Rats were given an intraperitoneal injection of Trop, MDL, or vehicle (Veh), just before introducing one of four diets: imbalanced amino acid diet +/- saccharin (Imb or ImbSac) or a balanced (corrected) diet +/- saccharin (Cor or CorSac). Subsequent aversion to saccharin was shown in preference tests using Cor and CorSac. Saccharin preference was significantly decreased (8.3% on test day 1) in the Veh/ImbSac group, but the Trop/ImbSac group's saccharin preference (57.8%) was similar to controls (49.6-70.3%); MDL also blocked the aversion to saccharin after ImbSac. This confirms previous reports of conditioned taste aversions with amino acid limitation and suggests a role for the 5-HT3 receptor in the development of these aversions.
Indispensable amino acids are neither synthesized nor stored in animals and are rapidly depleted ... more Indispensable amino acids are neither synthesized nor stored in animals and are rapidly depleted when not provided by the diet. To maintain homeostasis, organisms must sense deficiency of an indispensable amino acid and implement a repletion strategy. In rats and birds, the anterior piriform cortex houses the detector, but its mechanism has evaded description for >50 years. Recently, rapid detection of amino acid depletion was shown behaviorally when naïve animals, pre-fed a low nitrogen diet, terminated their first deficient meal within 20 min. The general amino acid control system of yeast, which is activated by amino acid deprivation via deacylated tRNA, was found to be active in rodent brain, showing conservation of amino acid sensory mechanisms across eukaryotic species.
We compared the vitamin B-6 status of 12-wk-old rats (n = 12) fed excess (1400 mg/kg diet) or the... more We compared the vitamin B-6 status of 12-wk-old rats (n = 12) fed excess (1400 mg/kg diet) or the recommended level (7 mg/kg diet, control) of pyridoxine (PN) hydrochloride to test if excess vitamin B-6 would cause tissue depletion of pyridoxal phosphate (PLP), the active coenzyme form of vitamin B-6. Plasma PLP, tryptophan-load test results, food intake, and tissue and body weights were not different at wk 6. Red blood cell endogenous alanine aminotransferase activity and PLP concentration were elevated (P less than 0.01) in rats fed 1400 mg PN.HCl/kg diet. In contrast, PLP concentration in muscle was significantly lower (P = 0.01) in rats fed excess vitamin B-6 (9.7 +/- 0.8 nmol/g, mean +/- SEM) than in controls (14.9 +/- 1.4). PLP concentration in other tissues, including plasma, was not affected. In rats fed excess vitamin B-6, pyridoxal was increased in all tissues examined (P less than 0.05), and total vitamin B-6 was increased in plasma, red blood cells and kidneys (P less th...
Transition from a normal- (NP) to a high-protein (HP) diet induces a rapid depression in food int... more Transition from a normal- (NP) to a high-protein (HP) diet induces a rapid depression in food intake and a progressive but incomplete return to the initial intake during the succeeding days. The aim of this study was to determine which CNS regions are involved in the HP diet-induced satiety in rats. Brains were collected from 3 groups of adult rats after habituation to an NP diet (21 d), during the transition phase to a HP diet (2 d), or after habituation to the HP diet (21 d). Fos expression was measured in several brain areas that are involved in the control of food intake (solitary tract nucleus, anterior piriform cortex, lateral hypothalamus, arcuate nucleus, posterior para ventricular nucleus, medio ventral hypothalamus, dorso medial hypothalamus, amygdala, and accumbens nucleus). Changes occurred in the majority of these regions during the transition period from the NP diet to the HP diet. After habituation to the HP diet, significant changes in Fos expression were restricted ...
Rats can adjust their nutrient intake in response to nutritional deficiency. This phenomenon has ... more Rats can adjust their nutrient intake in response to nutritional deficiency. This phenomenon has been described extensively for sodium deficiency, whereas other nutrient deficiencies have not been explored thoroughly. Essential amino acid (EAA) deficiency represents a relevant model to describe adaptive changes in behavior resulting from deficiency. The purpose of these experiments was to examine more closely the behavioral responses that occur as a result of lysine (LYS) and threonine (THR) deficiency. Licking to LYS, THR, glycine and distilled water during 10-s trials was measured in control (CON) and EAA-deficient rats. Licking tests were conducted both before and after 23-h intake tests. Although EAA-deficient rats did not show increased licking to the deficient EAA in any of the brief-access tests, in all cases, they did initiate significantly more overall trials than did CON. The EAA-deficient rats also had elevated intake of the deficient EAA in long-duration tests. These fin...
The present study investigated the relationship between endogenous CCK and serotonin (5-HT) in fa... more The present study investigated the relationship between endogenous CCK and serotonin (5-HT) in fat-induced satiety. Male Wistar rats with duodenal cannulas were adapted to eating 6 h/day along with receiving an infusion of saline or one of two isocaloric solutions (10 ml, 1 kcal/ml, 0.45 ml/min) varying in fat and carbohydrate content (20 or 80% energy from fat). Rats were infused 10 min after food presentation. The satiation/satiety response was determined from measures of meal size (MS), intermeal interval (IMI), and total food intake (TFI). Infusion with either fat solution reduced MS compared with saline; however, the 80% fat infusate reduced TFI and lengthened the IMI compared with saline and the 20% fat infusate. CCK and 5-HT involvement in fat-induced satiety was investigated by preceding the 80% fat infusate with CCK and/or 5-HT3 receptor antagonists Devazepide (Dev) and Tropisetron (Trop). A CCK releaser, trypsin inhibitor (TI), was added to the 20% fat infusate to enhance ...
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